Avildsen, Christina & Bie, Jennifer & Patel, Chirag & Sarvis, Brie & Rieboldt, Sarah & Speer, Brian R.: Ordovician PeriodUniversity of California Museum of Paleontology. 7.6.2011. Viitattu 12.01.2018.
Strömberg, C. & Guralnick, Rob & Simison, Brian & Speer, Brian & Cordero, Alicia: Lab IV - Early Land Plants (1)Lab IV. 1998. Viitattu 12.01.2018.
Dan Fischer & Liu, Tammy (Yue) & Yip, Emily & Yu, Korsen & Speer, Brian R.: The Silurian PeriodUniversity of California Museum of Paleontology. 7.5.2011. Viitattu 12.01.2018.
Speer, Brian R. & Grande, Rachel & Jean, Larry & Rowan, Aariel & Sumner, Angela & Tan, Amy & Rieboldt, Sarah & Smith, Dave: The Devonian PeriodUniversity of California Museum of Paleontology. 1.7.2011. Viitattu 11.01.2018.
Grande, Rachel & Jean, Larry & Rowan, Aariel & Sumner, Angela & Tang, Amy & Palmer, A.R. & Geissman, J. & Speer, Brian R.: Life of the DevonianUniversity of California Museum of Paleontology. marraskuu 2002. Viitattu 11.01.2018.
Waggoner, Ben & Speer, B. R.: Sphenophyta: Fossil RecordUniversity of California Museum of Paleontology. 9.14.1997. Viitattu 11.01.2018.
Waggoner, Ben M. & Hoe, Angela & Jusay, Azalea & Mayberry, Ray & Yu, Connie & & Speer, Brian R. & Rieboldt, Sarah & Smith, Dave: The Carboniferous PeriodUniversity of California Museum of Paleontology. 30.6.2011. Viitattu 11.01.2018.
Lingham-Soliar, Theagarten: ”2. The First Vertebrates, Jawless Fishes, the Agnathans”, The Vertebrate Integument Volume 1. Springer, 2014. ISBN 978-3-642-53747-9. Teoksen verkkoversio (pdf) (viitattu 12.01.2018). (Arkistoitu – Internet Archive)
Lingham-Soliar, Theagarten: ”2. The First Vertebrates, Jawless Fishes, the Agnathans”, The Vertebrate Integument Volume 1. Springer, 2014. ISBN 978-3-642-53747-9. Teoksen verkkoversio (pdf) (viitattu 12.01.2018). (Arkistoitu – Internet Archive)